Powder briquette/x-ray fluorescence analysis of major and minor elements in alkali-washed fly ash of municipal solid waste

X-ray fluorescence (XRF) analyses of 13 major and 5 minor components in alkali-washed fly ash of municipal solid waste were developed using powder briquette method. Fly ash samples were ground for 80 min using a ball mill to prepare reproducible powder briquette. The resultant particles had 12-mu m modal diameter and gave good reproducibility (3.2%). Calibration curves for analyses of 13 major and 5 minor elements required 16 reagents containing 18 analytes. They were ground for 20 min by ball milling after 80-min mixing with a V-type mixing machine or 2-h manual mixing using an alumina mortar. Lower limits of detection corresponding to 3 times the standard deviation (n = 6) for blank measurements were: Na2O,23 ppm; MgO, 22 ppm; Al2O3, 24 ppm; SiO2, 21 ppm; P2O5, 3.0 ppm; SO4, 3.1 ppm; Cl, 232 ppm; K2O, 51 ppm; CaO, 26 ppm; TiO2, 32 ppm; Cr, 6.3 ppm; MnO, 7.2 ppm; Fe2O3, 18 ppm; Ni, 5.3 ppm; Cu, 4.7 ppm; Zn, 5.4 ppm; Br, 4.7 ppm; and Pb, 4.6 ppm. This method was applied to analyses of 13 major and 5 minor elements in fly ash samples, which mainly consisted of Al2O3, SiO2, Cl, and CaO. Several thousand parts per million of Zn and Pb were included in most fly ash samples; Cl and Br were analyzed though their volatile characteristics. Copyright (C) 2008 John Wiley & Sons, Ltd.